(1) Field of the Invention
The present invention relates to barrel plating apparatus for forming, by electroplating or electroless plating, a layer on surfaces of articles formed of ceramics such as zirconia for use as resistors, condensors or other electrical parts or elements mounted on printed circuit boards for example.
(2) Description of the Prior Art
Among known plating apparatus as noted above, there is a horizontal barrel plating apparatus of the partial immersion type which comprises a pair of vertical plates opposed to each other in spaced relationship, and a hexagonal hollow barrel extending between and rotatably supported by the vertical plates to be driven by an AC motor. The hollow barrel includes a tubular barrel wall extending between blank plates disposed at opposite ends of the barrel, and this barrel wall is formed of a porous plate throughout.
In electroplating surfaces of ceramic articles or elements such as of zirconia (ZrO.sub.2) by using the above barrel plating apparatus, the articles are coated with a nickel layer by electroless plating in advance and then the articles coated with the nickel layer are placed in the hollow barrel for electroplating. With the conventional barrel plating apparatus, the articles are subjected only to a negative or passive agitating action of the barrel in rotation. Consequently, the agitation of the articles tends to be insufficient thereby to give rise to the problem of lack of uniformity in the plating thickness and adhesive failure.